Means for illuminating



YJuly 12, 1949. 1 M. HQFF 2,476,257

MEANS FOR ILLUMINATING DEPRESSIBLE KEYS July 12 1949- J. M. HOFF MEANSFOR ILLUMINATING DEPRESSIBLE KEYS 4 Sheets-Sheet 5 Filed April l5, 1946INVENTOR, TE ELTL M. HUH

MAD@ l ATTORNEYS July 12, 1949. J M, HOF..- 2,476,257

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Patented July 12, 19,49

MEANS FOR ILLUMINATING DEPRESSIBLE KEYS Jean M. Hoff, Evanston, Ill.Application April 15, 1946, Serial No. 662,379

17 Claims.

This invention relates to visual signalling and more particularly tomeans for signalling the position of a manipuiatable member, whichmember is adapted to actuate a mechanism. One illustrative applicationof the invention is to the iliumination of the depressible keys of acalculating machine.

An important object of the invention is to provide means forilluminating members, such as keys, plungers, throttles, switch buttonsand the like, by means of light rays passing through the members, incontra-distinction to light rays reiiected from the surfaces of suchmembers, so that the relative positions of the members may be visuallyindicated. Thus, when the operator of a calculating machine, forexample, notes a certain colored light shining from a certain key hewill know whether the key is depressed or not and, thus, he will becomeaware of the accidental position of any of the keys.

another important object is to provide visual signalling means, whereinthe visual signals are rays of light transmitted through manipulatablemembers during portions of their movement. As a result, all the members,when not manipulated, be of the same color but, as soon as a member ismoved, it will change color, due to light rays of a color, differentfrom'that of the non-manipulated members, passing through themanipulated one. Thus, the manipulated members will visually diier fromthe non-manipulated members, and both will be readily recognized.

A further important object is to provide means as described, wherein themembers, such as keys, contain light rays-transmitting portionscooperating with other portions, so that, as the operator looks downupon the members, he will see, at a glance, whether one or more membershave been manipulated. Thus, the visual signals are not provided byportions colored differently (as by enamel coatings) than are otherportions, but the signals are in the nature of iight rays passingthrough certain portions of the members.

Such enamel and similar coatings wear off, chip,

and become smudged.

Since the position of a depressible key of a calculating machine cannotbe readily recognized when looking directly down upon it, this inventionprovides a means for the ready recognization of depressed keys by anoperator looking directly down upon the keys.

Yet another object is to provide a novel depressible key for use incalculating machines and the like.

l. will be apparent during the following detailed description of theinvention, taken in connection with the accompanying drawings, forming aportion of this specification, and in which drawings Figure l. is a topplan of one embodiment of the invention, for association with asubstantially flat-surfaced machine, such as many calculating machines.

Figure 2 is an enlarged fragmentary longitudinal section, substantiallyupon the line 2 2 ot Figure 1.

Figure 3 is a fragmentary transverse section, substantially upon theline 3--5 of Figure 1, including two non-depressed keys.

Fi-gure 4 is a like section, but showing one key depressed.

Figure 5 is a fragmentary top plan of a corner of the novel device withthe keys thereof in horlzontal section.

Figure 6 is a fragmentary transverse section, somewhat like Figure 3 butof another embodiment of the invention.

Figure 7 is a fragmentary longitudinal section, somewhat like Figure 2,but on a reduced scale, of the embodiment of the invention as in Figure6.

Figure 8 is a section, somewhat like that of Figure 4 but of theembodiment of the invention of Figures 6 and 7.

Figure 9 corresponds somewhat with Figure but is of the inventionsembodiment as in Figures 6, 7 and 8.

Figure 10 is a fragmentary top plan of the embodiment of the inventionin Figures 6 to 9 inclusive.

Figure 11 is a transverse sectional view, somewhat akin to that ofFigures 3 and 6, of a third embodiment of the invention.

Figure 12 is a sectional view of this third embodiment, and correspondssomewhat with the showings in Figures 4 and 8.

Figure 13 is a fragmentary top plan of a corner of the embodiment inFigures 11 and l2.

Figure 14 is a top plan of this adaptation.

Figure 15 is a longitudinal section through an adaptation of theinvention to an arcuate surfaced machine, such las a cash register.

Figure 16 is a top plan of an adaptation of the invention to a widemachine.

Figure 17 is a vertical section, upon substantially the line l'l-l'l ofFigure 16.

Figure 18 is a fragmentary transverse section, somewhat like Figure 3but showing a modication of the structure.

In the drawings, wherein for the purpose o! Other objects and advantagesof the invention illustration are shown a preferred and three larrasarmodified forms of the invention, and wherein similar referencecharacters designate corresponding parts throughout the several views,the letter A designates the preferred form, the letter B one modiiiedform, C another modification, and D a third modification. By way ofillustration form A is shown in Figures 1 to 5 inclusive for associationwith a machine as a calculating machine, having a substantially iiatouter surface from which .the keys are adapted to project, and inFigures 14 and 15 for association by way of illustration, with a machineas a cash register, having an arcuate outer surface, from which the keysproject.

The form A shown in Figures 1 to 5 inclusive, includes a main housing2li, a plurality of manipulatable members 2l, extending outwardly of thehousing 25, and operatively connected with a mechanism adapted .to bemoved by the members 2l, a body portion 22 within the housing andassociated with the members 2l, an auxiliary' For 4 side walls 32 and 33may also form the side walls of the housing 23 but, since the latter is,preferably, higher than the housing 2li those portions of the Walls 32and 33 forming the side walls of the housing 23 are also higher. Thebottom wall 35 may be the bottom wall of the auxiliary housing and itmay be,l also, the top wall of the machine with which the novel meansis'v associated. This wall 36 is, preferably, provided with a pluralityof perforations 38 substantially corresponding in size with, and axiallyaligned with, the perforations 3i. The bottom wall 35 may, of course, bedisposed upon the top wall of the machine with the conventionalopeningstherein, for the keys or the like, axially aligned with the perforations3l and 38. The various walls mentioned may be of metal or opaquehardened plastic.

The members 2l may be independently operable keys, adapted forreciprocation and, in Figures 1 to,5 each of these is shown as having acylindrical body defining an upper or ngerengaging face 4I, a lower face42 and a peripheral surface 43, with a stern 44 extending from the axialcenter of the face 42. The stem 4, of course, iswoperatively connectedwith the mechanism adapted to be actuated upon manipulation of themembers 2|. In the example shown, the members 2l are reclprocated. Thatis, upon pressure of a finger-'upon an upper face 4l, the member 2l willbe depressed and normally retained depressed until a certain result (asa total) is desired, whereupon other mechanism (not shown) ismanipulated and one of the results thereof isv that the depressed membersprings upwardly into a non-depressed position.

Each body 40 shown in form A is composed of a light transmitting portion55 and on opaque portion 56. The portion 55 may be of glass, hardenedplastic, as Lucite, or the like. Translucent material is preferred andthe portion 55 is the uppermost portion of the body 40 while the pordtion 56 is of less height and may be a relatively thin metallic orhardened plastic disc secured to the portion 55, below the same, as bycement.

The body portion 22 preferably comprises several superposed sections,each provided with a' plurality of openings or perforations axiallyaligned with the perforations 3i and 38. Uppermost is a lightrays-blocking section 5@ which may be a layer of felt or other iibrousmaterial. Its function is to cut off or block any light rays projectedbetween the peripheries of the bodies iii and walls of the perforations3 l, so that a characteristic of the material of the section t@ is totend to hug the peripheral surfaces i3 of the bodies fill, even duringtheir reciprocable motion. Below the section 52 are two lightrays-transmitting sections 5i and 52.. These may be glass or hardenedplastic sheets, such as Lucite. Between the sections 6l and 62 is asection 53 of opaque but, preferably, light-reflecting material and uponthe upper surface of the section 5i may be a section 6ft of opaque but,preferably, light-reflecting material. These may be sheets of tinfoil,coatings of mercury, aluminum paint or the like. They are adapted toreflect light rays so that the rays will be transmitted to the portions55 of the bodies d0. It will be noted, in Figures 3 and 4, that,preferably, the sections 50 and `52 end at the wall 35 while thesections 6|, 62 and S3 extend into the slot 31 with their edgespreferably providing a substantially vertical face for partial supportof the insert 2Q- to be subsequently described.

It will be seen in Figure 3 that the nondepressed bodies 4B are sodisposed that the disclike, opaque portion 55 is in the same horizontalplanes as is the section 63. Since the section t3 is opaque, it and theopaque portions 56 form a substantially continuous opaque body.

Referring to the auxiliary housing 23, shown more particularly inFigures 1, 3 and 4, the same has an upper wall 65, and an end wall 56joining the upper wall 55 and side walls 32 and 33 which latter twowalls join, of course, the end wall 3d. This aumliary housing 23contains the light source 25 and, in order .to provide for circulationof air therethrough suitable Ventilating openings may be provided, asthe openings 61 in the upper wall 55 and openings -68 in the bottom wall36. So that light rays from the source 25 will not shine through theopenings 51, into the operators face, a shield 63 spaced above theseopenings may be provided and supported by uprights 1D. If desired, theinner face of the end wall 66 may be provided with a section 1l of lightreiiecting material. Whilejfor the purpose of clarity, the structures 25and 23 are described separately, it is obvious that the enclosure forthe structures 22, 24 and 25 may be considered as one, divided by thewall 35.

The insert 24 is, preferably, a section 15 of glass or substantiallytransparent hardened plastic material. It may be thin and extendlongitudinally of the housing 23 in face to face engagement with thesubstantially vertical face menored material, and the plane of the lineof division 81 of opaque material.

example, a band of metal or opaque hardened between the two portions 11and 18 extends longitudinally through the section 63. As a result,

- since this line of division registers with the section 83 and theportion 11 registers with the edge'of the section 6| while the portion18 registers with the edge of the section 62, when the rays from thelight source 25 travel through the colored portion 11 and thence throughthe section 6 i, they will illuminate the upper portion 55 of the body40 but the rays travelling through the colored portion 11 and thencethrough the section 6| are blocked by the opaque section 62 and opaquematerial of the disc-like portion 56 of the bodies 40.

However, when a body 40 is depressed, as is the right hand one in Figure4, the light rays travelling through the section 6| may travel throughthe upper portion 55 of the body 40, since the disclike portion 56 isnow below the horizontal planes of the section 62. As a result, theoperator, when all bodies 40 are not manipulated, will see green raysshining through all the bodies 40 but, as soon as a body is depressed,the rays will be yellowish green and he will be able to see, at aglance, the differences in color and note a depressed body 40 whichshould not be in that position. The light source 25 may be a so-callediiuorescent tube extending longitudinally of the auxiliary housing 23,paralleling the insert 24 and supported, at either end, by conventionalbrackets 19. Obviously, the insert 24 may be dispensed with and thesections 6| and 62 comprise glass or plastic each of a differentcolor'or shade, or one may be clear colorless glass or plastic and theother colored. It is also obvious that one or both sections may be ofseveral colors arranged in bands longitudinally of the sections.

Referring to form B of Figures 6 to 10 inclusive, where parts similar tothose of form A are shown like freference characters are employed. Infact the difference between form A and B is in the construction of themanipulatable members which are designated as 80 and may be keys adaptedfor reciprocation. Each preferably comprises a cylindrical body 8|defining an upper or finger engaging face 82, a lower face 83 and aperipheral surface 84, with a stem 44 extending from the axial center ofthe face 83. Each body 8| is composed of an uppermost,light-transmitting portion 85 and a lowermost opaque portion 86. Theportion 85 may be of translucent glass, hardened plastic (as Lucite) andthe like. The lowermost portion 86 is secured to the portion 84 in anyapproved way, as by cement.

It should be noted in Figure 8 that the intermediate part of theuppermost portion 85 is reduced peripherally and accommodates an inlayThis inlay may be, for

plastic material. It will be appreciated, from Figure 8 that, when thebodies 8| are in a non-depressed position (as is the left-hand body 8|),light rays travelling through the section 6| will also travel throughthe uppermost portion 85 but rays travelling through the section '62will be blocked by the disc-like portion 86. However, when a body 8| isdepressed (as the right-hand one of Figure 8 which is also the upperrighthand one of Figure 9), light rays travelling through the section 6|will be blocked by the inlay 81 but the disc-like portion 86 will nolonger block the rays, travelling through the section 62, and they maytravel through the portion 85.

Form C illustrated in Figures 11 to 13, differs from form A in thearrangement of the body portion 80 to take the place of the body portion22 tion 9| is like theuppermost section 60 of the body portion 22, andprovided for the same purpose. Below the section 8| is but one lightraystransmitting section 82 which may have a section 93 of opaque butlight-reflecting material upon its upper face. The section 92 extendsinto the opening 31. This section 82 may be clear, uncolored glass orhardened plastic or may be colored glass or hardened plastic either ofone or several horizontal layers of color. Since the bodies 46 of form Cmay be like those of form A, it is obvious that their disc-like portions56 will cooperate with the section 93 to block light rays travellingthrough the section 92 from reaching the upper light-transmittingportion 55 of the the latter is in the position of the left-hand body 40of Figure 12 but when the body 40 is depressed, like the right-hand body40 of Figure 12, which is the upper right-hand body 40 of Figure 13,these rays are not blocked. By the use of form C, there will be lightrays travelling through the body 40 only when the latter is depressed.

Form D shown in Figure 18 is quite similar to form A but the section 63of opaque material of form A is omitted and the two lightrays-transmitting sections 6| and 62 of Lucite are shown in face-to-facecontact in Figure 18, in their association with the rest of the means totransmit light rays of two colors. In addition, the opaque portions 56of the keys 2| areomitted, and the lower faces 42 of the keys, when thekeys are not depressed, are in substantially the same plane as thecontacting faces of the sections 6| and 62. This modification is founddesirable in some cases, particularly where Lucite is employed for thesections 6| and 62 and the key bodies. While -it would not appear, atfirst, desirable to provide the construction disclosed in Figure 18, theworth of this construction has been proven by me and it will be foundthat the depressed keys are easily and readily distinguished from thenon-depressed keys and vice versa. Reference characters, similar tothose employed in Figure 3 are used for corresponding parts in Figure18.

Figures 14 and 15 illustrate the application of the invention to amachine having a curved outer surface, such as some conventional cashregisters. For illustration, the dual auxiliary housings 23, inserts 24and light sources 25 of Figures 16 and 17 are disposed at the sides ofthe main housing which is designated as |00, instead of at the endsthereof and, of course, the two side walls |0I and |02 of the mainhousing |00 are provided with the openings |03, corresponding with theopening 31.

Figures 16 and 17 illustrate the employment of dual auxiliary housings23 disposed at both ends of the main housing 20, dual inserts 24 anddual light sources 25. This construction is particularly adapted to theuse of the invention with a wide machine, although it may be, in somecases, desirable to employ dual light sources 25 in narrow machines forincrease or evening of the intensity of the lightfrom the keys.

From the foregoing it is seen that the operator of the means disclosedherein, when one of the manipulatable members 2| or 80 is depressed,will be quickly aware that such member has been depressed because themember will change color,

body 40, when 7 and when the member has again assumed its non-depressedposition, it will have again changed color and, as it changes color,will be readily noted.

Various changes may be made to the forms of the invention herein shownand described without departing from the spirit of the invention orscope of the claims.

What is claimed is:

l. In means for illuminating keys, a housing, a plurality ofreciprocable keys extending therefrom, each key including a lightrays-transmitting portion, means to slidably accommodate at least a partof each key, comprising a body of light rays-transmitting materialwithin said housing and provided with a plurality of openings, one foreach key, and means for projecting light rays through said body andthrough at least a part of any one of said keys when at least a part ofsaid light rays-transmitting portion thereof is within its opening insaid body. l

2. In means for illuminating keys, a housing, a plurality ofreciprocable keys extending therefrom, each key including a lightrays-transmitting portion and an opaque portion, means to slidablyaccommodate at least a part of each key, comprising a body of lightrays-transmitting material and a body of opaque material above saidfirst-named body within said housing and provided with a plurality ofopenings, one for each key, and means for projecting light rays throughsaid first-named body and through at least a part of any one of saidkeys when at least a part of said light rays-transmitting portionthereof is within its opening in said body, said opaque portion beingconstructed and arranged to normally register with said body of opaquematerial when said keys are in one position.

3. In means for illuminating keys, a housing, a

plurality of reciprocable keysextending therefrom, each key including alight rays-transmitting portion and an opaque portion below Saidiirst-named portion, means to slidably accommodate at least a part ofeach key, comprising a body of light rays-transmitting material and abody of opaque material above said first-named body within said housingand provided with a plurality of openings, one for each key, and meansfor projecting light rays through said first-named body and through atleast a part of any one of said keys when at least a part of said lightraystransmitting portion thereof is within its opening in said body,said opaque portion being constructed and arranged to normally registerwith said body of opaque material when said keys are in one position. l

4. In means for signalling the positions of reciprocable keys, ahousing, including an upper opaque wall provided with a plurality ofspacedapart openings, a plurality of keys, one projecting outwardly ofeach opening and slidable therein, each key having a lightrays-transmitting port-ion and an opaque portion below said firstnamedportion, means to slidably receive at least a part of each key,comprising a body having a plurality of openings, one for each key, saidbody being provided with an outermost section of light rays-transmittingmaterial, an intermediate section of opaque material and an innermostsection of light rays-transmitting material, the thickness of saidintermediate section being 'substantially the same as the thickness ofsaid opaque portion, a light source, and means cooperat'ing with saidlight source for projecting light rays of one color through said uppersection and for projecting light rays of another color vthrough saidlower section, including a light rays-transmitting insert interposedbetween said light source and said sections, said insert having an upperportion of one color and a lower portion of another color with saidupper section and portion in register and said lower section and portionin register, the line of division between said sections registering withsaid intermediate section.

5. In means for signalling the positions of reciprocable keys, ahousing, including an upper opaque wall provided with a plurality ofspacedapart openings, a plurality of keys, one projecting outwardly ofeach opening and slidable therein, each key having a lightrays-transmitting portion and an opaque portion below said first-namedportion, means to slidably receive at least a part of each key,comprising a body having a plurality of openings, one for each key, saidbody being provided with an outermost section of light raystransmittingmaterial, an intermediate section of opaque material, having a lightrays-reecting surface, and an innermost section of lightraystransmitting material, the thickness of said intermediate sectionbeing substantially the same as the thickness of said opaque portion, alight source and means cooperating with said light source for projectinglight rays of one color through said upper section and for projectinglight rays of another color through said lower section, including alight rays-transmitting insert interposed between said light source andsaid sections, said insert having an upper portion of one color and alower portion of another color with said upper section and portion inregister and said lower section and portion in register, the line ofdivision between said sections registering with said intermediatesection.

6. In means for signalling the positions of retion of lightrays-transmitting material, the

thickness of said intermediate section being substantially the same asthe thickness of said opaque portion, a light source, and meanscooperating with said light source for projecting light rays of onecolor through one of said sections, including a light rays-transmittinginsert interposed between said light source and said one of saidsections.

7. In means for signalling the positions of reciprocable keys, ahousing, a plurality of reciprocable keys extending outwardly andinwardly of said housing and each key having a periphery, a lightrays-transmitting portion, means within said housing to slidably receiveat least a part of each key, comprising a body having a plurality ofopenings, one for each key, said body being provided with an outermostsection of opaque material constructed and arranged to closely surroundthe peripheries ofsaid keys, a light raystransmitting section inwardlyof said outermost section and a section of substantially opaque materialalso inwardly of said outermost section, and means within said housingto project light rays through said light rays-transmitting section andthence through said light rays-transmitting portion of any of said keyswhen at least a part of said light rays-transmitting portion is withinits opening in said body.

8. In means for signalling the positions of reciprocable keys, ahousing, a. pluralityvof reciprocable keys extending outwardly andinwardly of said housing, each key having a periphery, a lightrays-transmitting portion and an opaque portion extending to saidperiphery and disposed inwardly of said first-named portion, meanswithin said housing to slidably receive at least a part of each key,comprising a body having a plurality of openings, one for each key, saidbody being provided with an outermost section of material constructedand arranged to closely surround the peripheries of said keys, a lightraystransmitting section inwardly of said outermost section and asection of substantially opaque material also inwardly of said outermostsection, and means within said housing to project light raysthrough'jsaid light rays-transmitting section and thence through saidlight rays-transmitting portion of any of said keys when said opaqueportions thereof are out of register with said opaque section.

9. In means for signalling the positions of reciprocable keys, a housinghaving an opaque wall provided with a plurality of openings, a pluralityof reciprocable keys extending outwardly and inwardly of said housingthrough said openings, each key having an outer end, an inner end, aperiphery, a light rays-transmitting portion at said outer end, anopaque portion at said inner vend and extending to said periphery, and asecond opaque portion of less length than said light rays-transmittingportion, spaced from said lrst opaque portion and said outer end andextending' about said periphery at said light rays-transmitting portion,means to slidably receive at least a part of each key, comprising a bodyhaving a plurality of openings, one for each key, said body beingprovided with .an outermost section of light rays-transmitting material,an intermediate section of substantially opaque material and aninnermost section of light rays-transmitting material, a light source,and means cooperating with said light source for projecting light raysof one color through said outermost section and for projecting lightrays of another color through said innermost section, including a lightraystransmitting member interposed between said light source and saidsections, said member having one portion thereof of one color and asecond portion thereof of another color with said one portion and saidoutermost section in register and said second portion and innermostsection l0 each key having an outer end, an inner end, a periphery, alight rays-transmitting portion at said outer end, an opaque portion atsaid inner end and extending to said periphery, and a second opaqueportion of less length than said light rays-transmitting portion, spacedfrom said iirst opaque portion and said outer end and extending aboutsaid periphery at said light rays-transmitting portion, means toslidably receive at least a part of each key, comprising a body having aplurality of openings, one for each key, said body being provided withan outermost section of light rays-transmitting material, anintermediate section of substantially opaque material and an innermostsection of light rays-transmitting material, a light source, and meanscooperating with said light source for projecting light rays of onecolor through said outermost section and for projecting light rays ofanother color through said innermost section, including a lightraystransmitting member interposed. between said light source and saidsections, said member having one portion thereof of one color and asecond portion thereof of another color with said one portion and saidoutermost section in register and said second portion and innermostsection in register, the line of division between said sections beingconstructed and arranged to register with said intermediate section, thelength of said second opaque portion being substantially the same as thethickness of said outermost section and the shortest distance betweenthe innermost edge of said second opaque portion and the adjacent firstopaque portion being substantially the same as the thickness either ofsaid innermost and outermost sections, said second opaque portion beingnormally disposed within its opening in said wall and outwardly of saidoutermost section.

11. In means for illuminating keys, a plurality of keys, each keyincluding a light rays-transmitting portion, means to slidablyaccommodate at least a part of each key, comprising a body of lightrays-transmitting material provided with a plurality of openings, onefor receiving each key, and means for projecting light rays through saidbody and through at least a part of any of said keys when at least apart of said light transin register, the line of division between saidsecf tions being constructed and arranged to register Y with saidintermediate section, the length of said second opaque portion beingsubstantially the same as the thickness of said outermost section andthe shortest distance between the innermost edge of said second opaqueportion and the adjacent iirst opaque portion being substantially thesame as the thickness of said innermost section.

10. In means for signalling the positions of reciprocable keys, ahousing having an opaque wall provided with a plurality of openings, aplurality of reciprocable keys extending outwardly and inwardly of saidhousing through said openings,

mitting portion thereof is within its opening in said body.

12. In means for signalling the positions of reciprocable keys, ahousing, including an upper opaque wall provided with a plurality ofspacedapart openings, a plurality of keys, one projecting outwardly ofeach opening and slidable therein, each key having a lightrays-transmitting portion and an opaque portion below said firstnamedportion, means to slidably receive at least a part of each key,comprising a body 'having a -plurality of openings, one for each key,said body being provided with an outermost section of lightrays-transmitting material, an intermediate section of opaque materialand an innermost section of light rays-transmitting material, thethickness of said intermediate section being substantially the same asthe thickness of said opaque portion, a light source, and meanscooperating with said light source for projecting light rays of onecolor through said upper section and for projecting light rays ofanother color through said lower section.

13. In means for signalling the positions of reciprocable keys, ahousing, including an upper opaque wall provided with a plurality ofspacedapart openings, a plurality of keys, one projecting outwardly ofeach opening and slidable therein, each key having a lightrays-transmitting portion and an opaque portion below said first-namedportion, means to slidably receive at least a part of each key,comprising a body having a plurality of openings, one for each key, saidbody being provided with an outermost section of light raystransmittingmaterial, in intermediate section of opaque material, having a lightrays-reflecting surface, and an innermost section of lightraystransmitting material, the thickness of said intermediate sectionbeing substantially the same as the thickness of said opaque portion, alight source and means cooperating with said light source for projectinglight rays of one color through said upper section and for projectinglight rays of another color through said lower section.

14. As an article of manufacture, a reciprocable key having a body,provided with an upper face, a lower face and an outer surface joiningsaid faces, a portion of said body, from and including one of said facesto short of the other face, being of -light rays-transmitting materialand surface covered, for a portion of its length, and intermediate itsends, with substantially opaque material, and another portion from saidother face to said iirst portion being of substantially opaque material,

15. In means for illuminating keys, a lighttransmitting body providedwith means to transmit light rays of one color, including a section oflight rays-transmitting material, and means to transmit light rays ofanother color,.including a section of light rays-transmitting material,said body being provided with a plurality of spacedapart openingsextending into said sections; a plurality of keys slidably disposedWithin said openings and constructed and arranged to be manipulated fromoutwardly of said body, eachl mit light rays from atleast the other ofsaid sec- 5 tions; and means to project light rays to said sections.

16. In means for illuminating keys, a plurality of keys, each keyincluding a light rays-trans 5 mitting portion, means to slidablyaccommodate at least a part of each key, comprising a body of lightrays-transmitting material provided with a pluralityoi key-receivingopenings, and means for projecting light rays through said body andthrough at least a part of any of said keys when at least a part of saidlight ray-transmitting portion thereof is within one of said openings.

1'7. In means for illuminating keys, a lighttransmitting body providedwith means to transmit light rays of one color, including a section oflight rays-transmitting material,.and means to transmit light rays ofanother color, including a section of light rays-transmitting materialwith said sections one above the other, said body being provided with aplurality of spaced-apart openings extending into said sections; aplurality of keys slidably disposed within said openings and constructedand arranged to be manipulated from outwardly of said body, each keyhaving an outer face and an inner face and a light rays-transmit tingportion such that when in one position, with the plane of said innerface being in substantially the same plane as the contacting faces ofsaid sections, said portion will transmit light rays from one of saidsections and, when in another position, said portion will transmit lightrays from at least the other of said sections; and means to projectlight rays to said sections.

JEAN M. HOFF.

REFERENQES @FEED The following references are of record in the ille ofthis patent:

STA'E'ES PA'I'ENTS Name Date Sampson et al Oct. 17, 1933 Andres Dec. 9,1941 Dohsmann et al June 2, 1942 Andres Oct. 12, 1943 Number

